The purpose of this project is to conduct research on statistical methodology problems related to the Branch's consulting activities. These efforts include the development of new statistical tests and the modification of existing procedures to meet specific Institute needs. BIBLIOGRAPHIC REFERENCE: Haseman, J.K. and Soares, E.R.: The distribution of fetal death in control mice and its implications on statistical tests for dominant lethal effects. Mutation Research 41: 277-288, 1976.